Termination of flat cables

ABSTRACT

An electrical connector member for use with insulated flat cable having a housing member with a bore extending therethrough. A plurality of contact spring members are mounted in the bore, each of said spring members terminating in a piercing surface. An actuating plate is adapted to be inserted in the bore and cause the spring member piercing surfaces to pierce the insulation of the flat cable and thus make contact with conductors in the flat cable. The actuating plate may be formed of rib members with each rib member being associated with one of the spring members. Further, the spring members may be mounted in the bore in an unstressed condition prior to insertion of the actuating plate. Moreover, the spring members may be in the form of semieliptical beam, with the end thereof having a pair of piercing surfaces formed thereon.

[ Feb. 1, 1972 ['54] TERMINATION 0F FLAT CABLES [72] Inventors: John W. Anhalt, La Crescenta; James W.

Maston, Altadena, both of Calif.

International Telephone and Telegraph Corporation, New York, NY.

22 Filed: Dec. 15,1969

21] Appl.No.: 885,033

[73] Assignee:

FOREIGN PATENTS OR APPLICATIONS Great Britain ..339/98 1,145,297 3/1969 GreatBritain ..339/99 Primary Examiner-Joseph H. McGlynn Attorney-C. Cornell Remsen, .lr., Walter J. Baum, Paul W. Hemminger, Charles L. Johnson, Jr. and Thomas E. Kristofferson [5 7] ABSTRACT An electrical connector member for use with insulated flat cable having a housing member with a bore extending therethrough. A plurality of contact spring members are mounted in the bore, each of said spring members terminating in a piercing surface. An actuating plate is adapted to be inserted in the bore and cause the spring member piercing surfaces to pierce the insulation of the flat cable and thus make contact with conductors in the flat cable. The actuating plate may be formed of rib members with each rib member being associated with one of the spring members. Further, the spring members may be mounted in the bore in an unstressed condition prior to insertion of theactuating plate. Moreover, the spring members may be in the form of semieliptical beam, with the end thereof having a pair of piercing surfaces formed thereon.

6 Claims, 7 Drawing Figures PA-IENTED FEB H972 Elf 539L891 SHEET 1 OF 2 INVENTOR. JOHN W A/VHALT. BY JAMES W. MASTDA/ mmm'rm 1 m2 SHEET 2 OF 2 INVENTOR. JOHN W fl/VHQLT (#711455 W MASTON v 1 TERMINATION F FLAT CABLES The invention relates, in general, to termination of flat cables and, more particularly, to a connector assembly for terminating conductors contained in fiat cables.

BACKGROUND OF THE INVENTION The use of electrical connectors for terminating conductors in flat cable has heretofore required stripping the insulating material from the cable in order to expose the conductors. Thereafter, a connector was clamped or soldered to each of the conductors of the cable. Such a procedure was not only expensive, but time consuming, and not completely reliable. To overcome the requirements of stripping, as well as soldering, or gripping of the conductor, improved termination devices utilized a contact element having conductor-gripping jaws. The jaws contain teeth which cut through the multiconductor dielectric material to provide connection with the underlying conductor.

To ensure positive backing to facilitate engagement with teeth on the jaws on the contact material, the cable is mounted about a rigid mandrel. Further, a wedge device is provided which is partially inserted into a throat between the jaws of the contact member of members in a manner that holds the jaws apart from their normal unstressed position, thus permitting free entry of the cable portion to be terminated between the jaws. Upon insertion of the cable between the jaws, the wedge device is forced between the cable to a more fully inserted position in the throat where the throat is enlarged to release the wedging action simultaneously with the movement of cable insertion. Thus, the jaws are allowed to return to their unstressed position, at which they bite at an angle with respect to the line of movement of the cable to pierce the dielectric covering of the cable. Such an arrangement is not only complex and expensive, but in view of the complexity, reliability becomes a major consideration.

In order to overcome the attendant disadvantages of prior art, flat conductor cable connectors in the present invention provide a simple arrangement wherein the flat conductor cable need not be stripped to expose the conductors prior to termination. Piercing spring members are provided which need not be loaded until the actual connection between the cable and the conductor occurs. The entire conductor assembly can be made from simplified parts and readily assembled.

The advantage of the invention, both as to its construction and mode of operation, will be readily appreciated as the same becomes better understood by reference to the following detailed description when consideredin connection with the accompanying drawings in which like referenced numerals designate like parts throughout the figures.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts a perspective view of a flat cable terminating connector partly in section;

FIG. 2 illustrates the flat cable connector in FIG. 1, in cross section;

FIG. 3 shows a perspective view of the spring contact member used in the connector of FIG. 1;

FIG. 4 illustrates the flat cable connector of FIG. 1 prior to insertion of the conductor;

FIG. 5 depicts the flat cable conductor of FIG. 4 with the actuation plate partially inserted;

FIG. 6 shows the flat cable connector of FIG. 4 with the actuation plate fully inserted; and

FIG. '7 illustrates a cross-sectional view of the conductor of FIG. 1 taken along the lines 77.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings there is shown in FIG. 1, a preferred embodiment of the invention which contains a connector assembly 12, formed of a plurality of receptacle connectors 16. It should be understood to one skilled in the art that each of the receptacle connectors 16 have a plug connector associated therewith.

The receptacle connector 16 comprises a plurality of contacts 22 whose front end is tapered as at 24 and which are adapted to be mated with contacts in a plug connector. The contacts are shown in greater detail in cross-sectional view mounted in the conductor in FIG. 2. Further, FIG. 3 illustrates the contacts 22 in perspective view. The contact 22 further comprises'an enlarged central portion 26 having a tine 28 formed therein. The rear end of the contact is formed of a semieliptical beam 32 having a slight bell 34 in the forward end which 'is formed integral with the portion 26 and rearpiercing surfaces 36 formed between a central end member 38. The use of a pair of piercing surfaces provides both contact redundancy and structural integrity. The contacts 22 are normally made of a high-copper bearing spring material such as phosphor bronze.

The receptacle housing is formed of an enlarged forward bore portion 42 which terminates in a forward facing shoulder 44. A reduced-diameter central bore portion 46 is interconnected to the forward bore portion 42 and terminates in a forward facing shoulder 48. A still further reduced rear bore section 52 interconnects the bore portion 46 with an enlarged rear bore portion 54. The junction of the rear bore portion 54 and the bore portion 52 containing an upper rearward facing shoulder 56 and a lower rearward facing shoulder 58. The rear bore portion 54 also contains a top wall surface 59 and a bottom wall surface 60.

The forward bore portion 42 contains a plurality of axially extending grooves 6264 along its top wall and bottom walls, respectively. The rear outer surface of the receptacle housing contains lip members 72 which extend in opposite directions and are used to mate with a shell boot 74 after interconnection of the contacts with the fiat cable.

The forward face of the receptacle housing has at either end, formed slightly to the rear of the front surface, a pair of flange portions 82. Each of the flange portions 82 contains in its forward facing surface a hexagonally shaped recess 84. Mounted by means of a screw 86 in the recesses 84 are polarizing posts 88. The posts 88 may be rotated in any one of three positions due to the hexagon shape of the recess 84 to thus vary the polarizing positions.

It should be understood, of course, that while a hexagonally shaped recess has been shown, other shapes may be used which, in turn, could vary the number of positions of the polarizing post.

Mounted on the top surface 90 of each of the connector housings are raised members 92 which mate with grooves 94 on the bottom surface of each of the receptacle connectors, allowing the receptacle connectors to be stacked and positioned. Further, rearwardly facing openings 96 in the housing allow screws 98 to be inserted therein and allow a washer 100 and a nut (not shown) to fasten the receptacle connectors together.

Plug connectors (not shown) for mating with the receptacle connectors 16 can have mounted therein a plurality of conventional fork-type contacts 122. The contacts 122 may contain releaseftines 124 for removing the contacts from the plug connector housing. Further, the rear end of the contact may contain crimping means 126 for connection of a wire 128 to the contact 122.

It shouldbe understood, of course, that while the plug connector may utilize contacts 122 for interconnection with conventional wires, other arrangements are possible. For example, the plug connector could as well be used to interconnect to flat cable similar to the manner depicted for the receptacle connector 12. The plug connector, however, forms no part of the invention.

Referring now to FIG. 7, there is shown a cross section of the flat cable utilized with the invention of FIG. 1. The cable comprises conductors 152 which are mounted within the insulating material 154. In order to make contact with the conductors 152 it is necessary to pierce the insulation material 154 or otherwise remove it.

Referring now to FIG. 4, there is shown a view of the receptacle connector broken away prior to insertion of the cable 150 therein. An actuating plate 162 contains a fiat top surface 164 and a bottom surface 166 having axially extending rib members 168 extending downwardly therefrom. The cable is inserted from the rear of the receptacle connector into the bore 54 until it reaches the lower rear facing shoulder 58 and thus the cable 150 is between the piercing surfaces 36 and the bottom surface 60 of the bore. Then the plate 162 is inserted from the rear of the receptacle connector, as shown in FIG. 5 with each of the rib members 168 forming an insulating barrier between adjacent contacts. The bottom surface 166 causes the beam portion to force the piercing surfaces 36 through the cable insulation, until the position shown in FIG. 6 is finally assumed. After contact has been made between the piercing surfaces 36 and the cable conductors 152 the boot 74 is slipped over the rear end of the connector so that it interlocks with the lip 72, thus forming a good moisture seal.

While the contacts 22 have been shown embodied in receptacle connectors it should be understood, of course, that the contacts could be included in plug connectors as well.

I claim:

1. An electrical connector member for an insulated flat cable comprising:

a plurality of contact spring members, each of said spring members being mounted in a bore formed in said connector member and terminating in a piercing surface which faces substantially toward one of the surfaces of said bore with a first clearance space being formed between said piercing surface and said one bore surface for insertion of a flat cable in said first clearance space, and

an actuating plate adapted to be inserted in a second clearance space between a second surface of said bore and said spring member for causing said piercing surface to pierce the insulation of said flat cable upon insertion of said actuating plate, said actuating plate containing rib members, each rib member insulating adjacent spring members, insertion of said plate causing said spring members to move and cause the piercing surface to pierce the cable insulation.

2. An electrical connector member for an insulated flat cable comprising:

a plurality of contact spring members, each of said spring members being mounted in a bore formed in said connector member and terminating in a piercing surface which faces substantially toward one of the surfaces of said bore with a first clearance space being formed between said piercing surface and said one bore surface for insertion of a flat cable in said first clearance space, and

an actuating plate adapted to be inserted in a second clearance space between a second surface of said bore and said spring member for causing said piercing surface to pierce the insulation of said flat cable upon insertion of said actuating plate, said spring member being formed of a semieliptical beam which maintains a constant force on the piercing surface cable joint upon insertion of said actuating plate.

3. An electrical connector member comprising:

a cable member having a plurality of individual conductors formed in a plane and interspaced in a layer of insulation;

a bore formed in said connector member having a first surface and a second surface, one side of said cable member resting against said first bore surface;

a plurality of contact spring members, each of said spring members being mounted in said bore and terminating in a piercing surface which faces toward said first bore surface and a nonpiercing surface which faces toward said second bore surface; and

an actuating plate means adapted to be inserted in said bore between said nonpiercing spring member surface and said second bore surface for causing said piercing surface to pierce the insulation of said cable upon insertion of said actuating plate. 4. An electrical connector member in accordance with claim 3 wherein said spring member is in an unstressed condition prior to insertion of said actuating plate.

5. An electrical connector member in accordance with claim 3 wherein said flat cable is inserted in said first clearance until it abuts a shoulder formed in said bore.

6. An electrical connector member in accordance with claim 3 wherein each of said spring members have a pair of piercing surfaces. 

1. An electrical connector member for an insulated flat cable comprising: a plurality of contact spring members, each of said spring members being mounted in a bore formed in said connector member and terminating in a piercing surface which faces substantially toward one of the surfaces of said bore with a first clearance space being formed between said piercing surface and said one bore surface for insertion of a flat cable in said first clearance space, and an actuating plate adapted to be inserted in a second clearance space between a second surface of said bore and said spring member for causing said piercing surface to pierce the insulation of said flat cable upon insertion of said actuating plate, said actuating plate containing rib members, each rib member insulating adjacent spring members, insertion of said plate causing said spring members to move and cause the piercing surface to pierce the cable insulation.
 2. An electrical connector member for an insulated flat cable comprising: a plurality of contact spring members, each of said spring members being mounted in a bore formed in said connector member and terminating in a piercing surface which faces substantially toward one of the surfaces of said bore with a first clearance space being formed between said piercing surface and said one bore surface for inseRtion of a flat cable in said first clearance space, and an actuating plate adapted to be inserted in a second clearance space between a second surface of said bore and said spring member for causing said piercing surface to pierce the insulation of said flat cable upon insertion of said actuating plate, said spring member being formed of a semieliptical beam which maintains a constant force on the piercing surface cable joint upon insertion of said actuating plate.
 3. An electrical connector member comprising: a cable member having a plurality of individual conductors formed in a plane and interspaced in a layer of insulation; a bore formed in said connector member having a first surface and a second surface, one side of said cable member resting against said first bore surface; a plurality of contact spring members, each of said spring members being mounted in said bore and terminating in a piercing surface which faces toward said first bore surface and a nonpiercing surface which faces toward said second bore surface; and an actuating plate means adapted to be inserted in said bore between said nonpiercing spring member surface and said second bore surface for causing said piercing surface to pierce the insulation of said cable upon insertion of said actuating plate.
 4. An electrical connector member in accordance with claim 3 wherein said spring member is in an unstressed condition prior to insertion of said actuating plate.
 5. An electrical connector member in accordance with claim 3 wherein said flat cable is inserted in said first clearance until it abuts a shoulder formed in said bore.
 6. An electrical connector member in accordance with claim 3 wherein each of said spring members have a pair of piercing surfaces. 